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authorAndrey Konovalov <[email protected]>2019-02-20 22:19:28 -0800
committerLinus Torvalds <[email protected]>2019-02-21 09:01:00 -0800
commit18e506610238eda2b0c5a19a123d3d6ec0ab2de6 (patch)
tree5bf9bf113ab2878a17ac1135e271fd5c58a1ce21
parenta71012242837fe5e67d8c999cfc357174ed5dba0 (diff)
kasan, slub: fix conflicts with CONFIG_SLAB_FREELIST_HARDENED
CONFIG_SLAB_FREELIST_HARDENED hashes freelist pointer with the address of the object where the pointer gets stored. With tag based KASAN we don't account for that when building freelist, as we call set_freepointer() with the first argument untagged. This patch changes the code to properly propagate tags throughout the loop. Link: http://lkml.kernel.org/r/3df171559c52201376f246bf7ce3184fe21c1dc7.1549921721.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <[email protected]> Reported-by: Qian Cai <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Vincenzo Frascino <[email protected]> Cc: Kostya Serebryany <[email protected]> Cc: Evgeniy Stepanov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
-rw-r--r--mm/slub.c20
1 files changed, 7 insertions, 13 deletions
diff --git a/mm/slub.c b/mm/slub.c
index a7e7c7f719f9..80da3a40b74d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -303,11 +303,6 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
__p < (__addr) + (__objects) * (__s)->size; \
__p += (__s)->size)
-#define for_each_object_idx(__p, __idx, __s, __addr, __objects) \
- for (__p = fixup_red_left(__s, __addr), __idx = 1; \
- __idx <= __objects; \
- __p += (__s)->size, __idx++)
-
/* Determine object index from a given position */
static inline unsigned int slab_index(void *p, struct kmem_cache *s, void *addr)
{
@@ -1664,17 +1659,16 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
shuffle = shuffle_freelist(s, page);
if (!shuffle) {
- for_each_object_idx(p, idx, s, start, page->objects) {
- if (likely(idx < page->objects)) {
- next = p + s->size;
- next = setup_object(s, page, next);
- set_freepointer(s, p, next);
- } else
- set_freepointer(s, p, NULL);
- }
start = fixup_red_left(s, start);
start = setup_object(s, page, start);
page->freelist = start;
+ for (idx = 0, p = start; idx < page->objects - 1; idx++) {
+ next = p + s->size;
+ next = setup_object(s, page, next);
+ set_freepointer(s, p, next);
+ p = next;
+ }
+ set_freepointer(s, p, NULL);
}
page->inuse = page->objects;